A MANET network (Mobile Ad-hoc Network) is a kind of ad-hoc network that has the capability to reconfigure itself and change locations. Such a network is composed of a plurality of moving communication nodes that are able to receive/transmit data from/to each other.
In this specification the term node embraces equipments that can transmit and receive on a selected radio channel.
The term data embraces signalling or user traffic or any kind of traffic.
A MANET network can use a single radio channel or a plurality of radio channels. Data communications are usually transmitted in time slots, a time slot being defined by its transmission time and its duration.
A time slot used by a given node to transmit on a given radio channel can be reused in transmission on the same radio channel by other nodes if they are far away enough and thus do not interfere.
Several nodes belonging to a MANET network may have a negative impact on performances because of their wide connectivity compared to the network average. A node with a wide connectivity is a node that can communicate with many other nodes.
This is due to good propagation conditions and/or a favourable location of the node among other nodes in the network.
This kind of node is called potentially disruptive node (PDN node). For example, a node with a high altitude location may be considered as a PDN node.
The major concern about PDN nodes is linked to their large number of neighbours. Indeed, PDN nodes can reduce the amount of slot spatial reuse that could take place in a network if these PDN nodes were not present. Moreover, PDN nodes can become routing bottlenecks if they have to relay too much data.
In the article position-based broadcast TDMA scheduling for mobile ad-hoc networks (MANETS) with advantaged nodes written by K. Amouris, IEEE, October 2005, a solution to the problem of spatial reuse due to PDN nodes is proposed. In this article, PDN nodes are named advantaged nodes. Those nodes have a large transmission/reception range. Due to their increased number of neighbours, the amount of slot spatial reuse that can take place in a MANET can be significantly reduced. The proposed solution is based on the fact that each node in the network is equipped with a GNSS receiver or some other terrestrial coordinate system through Time of Arrival (TOA) measurements. A spatial grid is used, the said grid delimiting a virtual geographical zone, and each node of the network belongs to a square of that grid. This enables to utilize Spatial TDMA access type, which is the adaptation of TDMA for mobile ad hoc networks and slot spatial reuse. A disadvantage of this solution is that all the nodes of the network have to be equipped with a global navigation satellite system (GNSS). Moreover, the solution is not satisfying, as advantaged nodes only have one dedicated slot to transmit per transmission cycle and they have to share it on a round-robin basis. The limitation on the use of one slot for transmissions from advantaged nodes to non-advantaged nodes may create bottleneck situations.